The present invention relates to a running vehicle control method for automatically controlling a plurality of vehicles running on a road.
A moving target method (hereinafter referred to as "MT method") is conventionally known as one of running vehicle control methods for automatically controlling vehicles running on a road.
In the MT method, as shown in FIG. 1, a virtual road 82 equivalent to a real road 81 is set on a driving management computer (not shown). Points (moving targets (MT)) 83 for ideal running are set at predetermined intervals on the virtual road 82, and actual vehicles are controlled to run on the real road 1 in pursuit of the MT 83.
An example of the system, to which the MT method is applied, will now be described with reference to FIGS. 2 and 3.
In FIG. 2, a road 90 comprises a looped main line 91 and at least one (three in FIG. 2) branch line arranged at a predetermined interval. The branch line 92 diverges from the main line 91 to a stop point 99 at which the vehicle stops/starts and converges to the main line 91 from the stop point 99.
As shown in FIGS. 2 and 3, the road 90 is provided with communication/position information equipment units 95 for performing communications with the running vehicles, controlling the vehicles, and acquiring position information on the vehicles. The vehicles are regularly driven according to MT signals generated from the equipment units 95 under control of the driving management computer.
The vehicle, which has advanced after temporarily stopping the stop point 99 on the branch line 92, enters an acceleration region 96 shown in FIG. 3. In order to make the vehicle (converging vehicle) on the branch line 92, which has entered the acceleration region 96 from the stop point 99, converge onto the main line 91, the following techniques are conventionally adopted. In one technique, the vehicle is started from the stop point in such a timing that the vehicle can timely catch the MT on the main line at a convergence point 94 (this MT on the main line being called "to-be-converged MT"). In another technique, all MTs assigned to the vehicles on the main line 91 are shifted so that the MT ("converging MT") on the branch line 92 can be assigned to the vehicle on the branch line 92 advancing to converge onto the convergence point 94.
Recently, with an increase in amount of transportation, there is an increasing demand for high-density running of vehicles.
However, the conventional running vehicle control method, to which the MT method is applied, is not suitable to the high-density running control system. If the conventional MT method is applied to the high-density running control system with no changes, the following problems will arise:
1) The vehicle, which runs before or after the to-be-converged MT on the main line 91 corresponding to the converging MT assigned to the vehicle on the branch line to be converged or runs on a main line of another traffic lane, is not necessarily subjected to the MT control. Thus, the safety for the convergence is not ensured.
2) When the MTs generated at predetermined intervals are used, the position of the to-be-converged MT is not necessary optimal in consideration of the vehicle run condition (e.g. traffic volume) on the true road. Thus, the safety for the convergence is not ensured.
The object of the present invention is to provide a running vehicle control method ensuring high safety for convergence/divergence of vehicles.